Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft. Left-over products of the combustion are exhausted out of the turbine.
Compressors and turbines typically include alternating stages of static vane assemblies and rotating wheel assemblies. The rotating wheel assemblies include disks carrying blades around their outer edges. To assemble each of the rotating wheel assemblies, roots of the blades are received by slots formed in each disk so that each disk and the blades carried by the disk are coupled together for common rotation. In operation of the rotating wheel assemblies, stresses applied to each disk and the blades received by each disk complicate the attachment of the blades to the disks. Designs of the roots of the blades and the corresponding wheel slots that decrease the stresses applied to the blades and the wheels during operation of the rotating wheel assemblies remain an area of interest.